The present invention relates to an instrument housing for industrial electronic systems, the housing including a steel sheet body intended to accommodate electronic units and provided with a front opening, a continuous frame strip extending inwardly at a right angle from the front opening so as to form an edge with the body, an outwardly oriented continuous knife-edge strip angled from the frame strip as well as a closed rectangular frontal frame attached to the front opening, seated ahead of the frame strip and the knife-edge strip and being provided with two long and two short lateral legs.
The proposed instrument housing is employed with different dimensions for independent table model instruments.
Instrument housings including a closed body and an attached frontal frame are known in various embodiments. To accommodate the electronic components, supporting elements and inserts for modules and circuit boards are provided within the body (EU-A1-0,311,702). However, in these housings the frontal frames can either not be exchanged at all or only in a very complicated manner; the unavoidable protection against the penetration of dust and splashed water is hardly ensured or is lost when the frontal frame is exchanged.
A branch-off box for electrical devices, particularly for electrical lines, is known which is protected against water sprays and is configured to be secure against access. One region of the upper portion of the housing is closed by a specially configured cover. As a seal, the upper housing portion is provided with an outwardly oriented knife-edge strip which follows at a right angle an inwardly projecting strip. A short web is provided at the cover, whose border profile has the shape of an L. The web is provided with a groove in which a seal is seated. With the cover closed, the knife-edge strip engages in the groove. However, this housing configuration, which does not include a frontal frame, is not suitable for use in conjunction with instrument housings for industrial electronic systems (German Utility Model Patent DE-GM 87/03,138).